Grommet making machine



w. A. YOUNG 2,224,754

GROMMET MAKING MACHINE Dec. 10, 1 I

Filed Nov. 2, 1939 2 Sheets-Sheet l 'M HIIHHIII .l """'lllllllll I'M W IIHHIIIIIII' Wz'llz'aka A. Young ATTORNEY.

' INVENTOR.

Dec..10, 1940. w. A. YOUNG 2,224,754

GROMMET MAKING MACHINE Filed Nov. 2, 1939 2 Shegts-Sheet 2 Patented Dec. 10, 1940 UNITED STATES PATENT OFFICE GROMJVIET MAKING MACHINE William A. Young, College Point, N. Y.

Application November 2, 1939, Serial No. 302,555

4 Claims.

Objects 'Among the principal objects which the present invention has in view are: to provide an improved 5 machine for making grommets; to insure a tight winding of the grommet; to provide for simplified driving of the twisting rollers; to enable the machine to manufacture any desired size of grommet; to eliminate expensive, heavy and bulky machine parts and to otherwise secure simplicity 1 of construction and operation; and to obtain other advantages and results as may be brought out in the following description.

Drawings Figure l is a side elevation of my improved machine embodying the invention;

Figure 2 is a view similar to Figure 1 and looking at the machine from the opposite side;

Figure 3 is a. top plan view of a portion of the machine;

Figure 4 is a front elevation, looking to the right of Figure 1;

Figure 5 is a sectional view taken on the line 5-5 of Figure 3;

Figures 6 and 7 are fragmentary views partly in section showing the position of the parts at the beginning of the formation of the grommet and the end of the forming operation, shown as taken on line 66 of Figure 3; and

Figure 8 is a side View of a finished grommet.

Description As will be seen in the drawings, the reference numeral l designates a suitable bench-like frame for carrying the various parts as a unitary assembly or machine. At the top of this frame of the present disclosure are provided a pair of supporting brackets l I and I2 at opposite ends of the bench top. A horizontally disposed mandrel assembly is positioned to extend through these two brackets and longitudinally slidable, therein. The said mandrel assembly comprises one end portion l3 which has a spiral groove M in its outer surface and which is engaged by a nut-like opening of the supporting bracket II in order to impart a rotation to the mandrel assembly when the said mandrel assembly is slid longitudinally.

The other end portion of the mandrel assembly preferably provides an outwardly tapering mandrel proper which is here shown as comprising a central rod l integral with and in axial continuation of the spirally grooved end l3. This rod portion [5 has a sleeve l6 thereon for the greater part of its length, said sleeve preferably being of rubber or suitable composition and fixed with respect to the rod so as to rotate and slide therewith. This sleeve is slightly larger at its end next the spirally grooved portion of the mandrel assembly so as to be smaller toward theprojecting free end of the mandrel. 5

The mandrel assembly is supported where passing through bracket l2 by an axially transverse roller ll suitably grooved to receive the curved surface of the sleeve [6 therein. This roller is conveniently carried by a vertical slide I 8 adjustably mounted in its vertical disposition by an adjusting screw I9. It will be observed by reference to Figures 1 and 2 particularly that the adjusting screw l9 passes through a transverse or horizontally disposed lip on the slide and that a spring 2| disposed upon the adjusting screw beneath said lip and engaging at its other end against the top of bracket l2 maintains the slide elevated against the head of the adjusting screw and enables the spring to thereby take up much of the vibration transmitted by the mandrel to the slide in operation.

Also carried by the bracket l2 are two arms, one of which 22 is located below the horizontal plane of the mandrel, and the other of which, 23, is located above such horizontal plane. Both arms are pivoted, as at 24, 25 respectively, to the bracket I2 and extend substantially horizontally in a direction toward the smaller end of the mandrel sleeve. The said arms are each provided 0 with a grooved roller 26, of which the grooved portions thereof is preferably surfaced with rubber or other suitable friction surface as clearly shown in Figure 7. The central planes of the two said rollers preferably are coincident and include the axis of the mandrel therein. The said rollers are furthermore each held with respect to the mandrel by suitable means such as adjusting screws 21, 28. Springs 29 on each of these adjusting screws between the roller arms and the screw mounting fro-m the bracket provide for the necessary vibration of the rollers as well as for the adjustment thereof to different sizes of mandrels and also the varying size of any one mandrel due to its taper.

The rollers 26, 26 are both driven in directions such that the portions of the surfaces of the rollers toward the mandrel are moving in a common direction with respect to each other. The particular and preferred drivingv means here shown comprises a single continuous belt 30 which, starting from a pulley 3| on a driving motor 32, extends upwardly to a lower pulley 33 for the lower roller 26, passes around that pulley down to an idler pulley 34 near the motor, around the idler pulley to the upper side of a pulley 35 for the upper roller 26 and thence downwardly to the motor pulley. Idler pulley 34 above mentioned is carried upon the upper end of an arm 36, the lower end of which is pivoted, and the upper end is drawn away from the rollers by a spring 31.

In operation a length of material, such as hemp, rope, lamp wick, jute, or the like, is given a hitch around the mandrel reasonably close to the rollers .26, and the mandrel assembly is then slid longitudinally to bring the rope-like material into engagement with said rollers. This engagement functions to wind the material into an annulus or grommet 38. As the twisting proceeds, the mandrel is slid, it being remembered that sliding the mandrel rotates the same by virtue of spiral groove l4, and therefore the twisting operation is performed progressively and around the entire grommet. When a grommet is completely formed it can be slid toward the smaller end of the mandrel and droppeddown a supporting cord 38' conveniently hung on the outer end of the mandrel assembly. It is preferable to provide a collar 39 at a mid-part of the mandrel assembly between brackets II and I2, said collar acting as a step or limit of longitudinal movement for the mandrel assembly in both directions.

I desire to emphasize in connection with the disclosure of the specific embodiment of the invention made in the drawings, and in the description that the mandrel assembly has what may be termed a floating support, and that the rollers which twist the grommet forming material are likewise provided with floating supports whereby a minimum of vibration introduced by the irregularities of the grommet forming material when partly or completely twisted, will be transmitted to the rest of the machine. This enables the machine to both theoretically and actually run much smoother than has heretofore been accomplished and greatly prolongs the life of the machine in addition to enabling the grommets to be more uniformly and perfectly constructed. The structure disclosed furthermore permits the rollers 26 to have a free action with respect to the grommets, that is to say, permits one roller to hesitate or move slower than the other roller if and when conditions require, that is to say, the

drive for the roller permits slippage with respect to one roller without necessarily slowing down the other roller and I find this results in a far better product than can be obtained with an enforced synchronization of the two rollers. Furthermore, the structure is such that the mandrel can be very readily exchanged for another of different size and with a very convenient adjustment of the twisting rollers consequent to the substitution.

I claim:

1. A grommet making machine as characterized comprising in combination with a support, a mandrel assembly, twisting rollers associated with said mandrel assembly for twisting material on said assembly into a grommet, and pivoted arms fioatingly mounting said rollers with respect to said mandrel, said arms having adjusting means and springs for retaining said arms in position.

2. A grommet making machine as characterized comprising in combination with a support, a mandrel carried thereby, rollers associated with said mandrel for twisting material on said mandrel into a grommet, and a common driving belt for said rollers permitting speed variations between the said rollers.

3. A grommet making machine as characterized comprising a combination with a support, a mandrel carried thereby, rollers associated with said mandrel for twisting material on said mandrel into a grommet, pivoted arms fioat'ingly mounting said rollers with respect to said mandrel, said arms having adjusting means and springs for retaining said arms in position, and a common driving belt for said rollers permitting speed variations between said rollers.

4. A grommet making machine as characterized comprising in combination with a support, a mandrel carried thereby, said mandrel having a spiral groove at one end portion thereof adapted to rotate said mandrel when slid longitudinally, rollers associated with said mandrel for twisting material on said mandrel as the mandrel is being rotated and moving longitudinally to form a grommet, and a common driving means for said rollers permitting speed variations between said rollers.

WILLIAM A. YOUNG. 

